US 12,189,259 B2
Electrophoretic core-shell particles having an organic pigment core and a shell with a thin metal oxide layer and a silane layer
Jay William Anseth, Canton, MA (US); Brandon MacDonald, Melrose, MA (US); and Craig Alan Breen, Arlington, MA (US)
Assigned to E Ink Corporation, Billerica, MA (US)
Filed by E INK CORPORATION, Billerica, MA (US)
Filed on Mar. 25, 2024, as Appl. No. 18/615,220.
Application 18/615,220 is a division of application No. 17/156,911, filed on Jan. 25, 2021, granted, now 12,025,901.
Claims priority of provisional application 62/970,901, filed on Feb. 6, 2020.
Prior Publication US 2024/0272510 A1, Aug. 15, 2024
Int. Cl. G02F 1/1675 (2019.01); C09B 67/08 (2006.01); G02F 1/167 (2019.01)
CPC G02F 1/1675 (2019.01) [C09B 67/0007 (2013.01); G02F 1/167 (2013.01); G02F 2001/1678 (2013.01); G02F 2202/022 (2013.01); G02F 2202/28 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of manufacturing of an electrophoretic medium, the electrophoretic medium comprising a plurality of a first type of core-shell particles and a non-polar fluid, each of the plurality of the first type of the core-shell particles comprising a core comprising an organic pigment and a shell comprising a metal oxide layer and a silane layer, wherein the method comprises the steps of:
providing organic pigment particles;
introducing the organic pigment particles into a fluidized bed reactor as a powder bed;
contacting the powder bed with a gaseous stream comprising an inert gas and a precursor of metal oxide;
contacting the powder bed with a gaseous stream comprising a reagent that reacts with the metal oxide precursor to form a metal oxide, wherein the reagent is selected from the group consisting of water, oxygen, ozone, or mixtures thereof;
reacting the organic pigment particles having a metal oxide layer with a silane compound in an organic solvent to form a silane layer, wherein the silane compound comprises a first functional group, a second functional group, and a third functional group, wherein the first functional group reacts with the metal oxide to form organic pigment particles comprising a metal oxide layer and a silane layer;
combining the plurality of core-shell particles and the non-polar fluid.